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High Fidelity Loudspeakers with Boronized Titanium Diaphragms

The boronizing process to titanium is developed to get high quality diaphragms for loudspeakers. A titanium diaphragm is buried in a mixed power of boron, carbon, and sodium carbonate, and heated. By this process, titanium borides in the form of TiB and TiB2 are obtained at the diaphragm surface. Ten minutes of treatment at 1,200 degree Centigrade to a 25µm thickness titanium diaphragm gives a Young's modulus of 2.7 x 1011 N/m2, density of 4.23 x 10 kg/m3 and boronized depth of 5 µm. The E/p of boronized titanium reaches to about three times of titanium. Using high Young's modulus bornonized titanium diaphragms, loudspeakers with wide-range, low-distortion, and excellent transient response can be realized.